The present invention relates to a drawer pull-out guide, including a carcass rail to be fixed to a furniture carcass, at least one extension rail which is displaceable relative to the carcass rail between a closed position and an open position, and at least one rolling body and at least one supporting body which are movable along a running limb of the carcass rail and a running surface of the extension rail upon a movement of the extension rail. A clearance is arranged on the running limb of the carcass rail and/or on the running surface of the extension rail, and the at least one rolling body is accomodated within the clearance in the closed position of the extension rail. The at least one rolling body is thereby relieved from the load of the extension rail such that, in the closed position of the extension rail, the load of the extension rail is carried by the at least one supporting body.
The invention further concerns an arrangement with a drawer pull-out guide of the kind to be described and with a drawer which is movable relative to a furniture carcass by way of the drawer pull-out guide in the mounting position.
With such drawer pull-out guides, the load of the drawer is transmitted by rolling bodies which are subjected to different loading conditions. After a longer standstill of the drawer in the closed position, the foremost rolling bodies—particularly because of the considerable weight of a drawer front panel—bear the greatest load which leads in the course of time to a peripheral deformation, flattening, or even to a breakage of the rolling bodies. Due to this mechanical stress exerted on the rolling bodies, the running behaviour and thus the functionality of the drawer pull-out guide can adversely be affected which results in a shorter lifetime.
A measure for avoiding such a flattening of rolling bodies is described in EP 2 079 342 B1 to the applicant. Here, a running carriage having a group of rolling bodies is displaceable between the rails, and at least one further load-transmitting element is supported on a front cantilever of the running carriage—with a spacing to the group of rolling bodies. In the closed position of the extension rail, the load of the drawer is carried by the load-transmitting element so that the group of rolling bodies, in the closed position, are substantially relieved and thus protected from deformation. In an open position of the extension rail, the load-transmitting element is moved over the front end of a rail of the drawer pull-out guide, and the load of the extension rail is carried by the group of rolling bodies. However, also in the closed position of the extension rail, the group of rolling bodies is partly subjected to a load which can lead to a deformation of the rolling bodies. Also, the construction of the shown running carriage is a special form which is relatively voluminous and causes extra manufacturing costs.
DE 197 51 384 A1 and GB 515,899 A each show pull-out devices for drawers, in which several rollers which are spaced from each other in the longitudinal direction of the extension rail are rotatably arranged on the extension rail. In the closed position, the rollers can run into dents of the stationary rail so that the rollers are relieved from the weight of the drawer and an undesired opening movement of the pull-out devices is prevented. A disadvantage is the fact that a relatively great force is required in order to open the pull-out device, because the rollers each need to be moved out of their associated dents. This leads to abrupt transitions when opening and closing the extension guides which adversely affect the running behaviour of the extension guide. Moreover, the diameters of the rollers are to be dimensioned relatively large for reasons of stability, whereby the installation space is significantly enlarged.